This proposal requests funding for a Compact, High-Performance Magnetic Resonance Imaging (MRI) System for in-vivo Rodent Imaging. Rodents are the most commonly used experimental animals in biomedical research. However, the VA San Francisco does not have rodent MRI imaging capability. Currently, projects that need to monitor internal structures and physiological functions within living rats or mice are hampered by the lack of a high-resolution rodent MRI system. Therefore, acquisition of a rodent MRI system will fulfill a critical need for multiple research projects at the VA SF. Eight major users and four minor users compose the first cohort of investigators who have expressed a critical need for this instrument. These investigators perform research in diverse research areas of Cancer, Cardiovascular, Musculoskeletal, Nephrology and Neuroscience. A high performance rodent MRI system will make possible precise measurements of multiple in- vivo parameters. For example, monitoring of: * Tumor location, mass, and shape * Ischemic regions in mouse brain and nerves * Cardiac structure, ventricular volumes and contractile function of all 4 chambers of the heart and the presence of ischemic injury * Skeletal muscle mass and ischemic injury * Integrity of joints, tendons and bone. Vascular imaging. * Kidney structure and damage Therefore, a rodent MRI system will aid the research of multiple projects in several areas of investigation that are critically relevan to veteran's health. These projects involve exploration of new therapies to treat brain injury, cancer, heart disease, musculoskeletal injury, orthopedic diseases, and renal failure. These diseases are highly relevant to the veteran patient population. The instrument requested is a Bruker ICON MRI system. This is a relatively low priced MRI system that has two innovative and significant technical advantages: First, the Bruker ICON MRI system uses a compact permanent magnet rather than a traditional superconducting MRI magnet. Therefore, the permanent magnet does not require cooling with cryogens. Accordingly, the significant costs and maintenance associated with a traditional superconducting magnet are not required. This system has no ongoing maintenance requirements. It does not contain parts that need regular replacement or replenishing. Second, the Bruker ICON MRI system uses a self-shielded permanent magnet, and therefore does not require additional external shielding. The magnet has negligible magnetic fringe fields outside of the magnet. Thus, the compact magnet can be housed in regular laboratory space and does not require a separate shielded location. Furthermore, the Bruker ICON system does not require MRI safety protocols that must be used with a traditional MRI system. In summary, acquisition of a rodent MRI system will address a significant research need, and will greatly aid many research projects in multiple fields covering diseases that are highly significant to the veteran patient population.